For his actions during the capture of Lutai on September 9, 1900, Flug was awarded the Gold Sword for Bravery on March 15, 1901.

On January 22, 1902, he became chief of staff of the Kwangtung Oblast, and was promoted to major general on August 27, 1903, for distinguishing himself.

On 4 October 1914, he was appointed to supervise the restoration of the 13th and 15th Army Corps, which had been all but destroyed in Eastern Prussia in August 1914.

As a result of the energy, courage and skilful leadership shown by General Flug, the German plan came to nothing.

After the February Revolution, Flug was put on 30 May 1917 in the reserve of officers at the headquarters of the Petrograd Military District.

On November 14, 1917, he arrived in Novocherkassk and offered his services to General Mikhail Alekseyev, who had formed the Volunteer Army.

During his mission to Siberia, he helped unify and coordinate the activities of the clandestine officers' organizations in Omsk, Petropavlovsk, Tomsk and Irkutsk.

Despite his extensive experience and involvement in the organization of the Anti-Bolshevik resistance in Siberia, there was no place for him in Kolchak's Army.

On February 10, 1919, Vasily Flug sailed from Vladivostok on the steamboat Tomsk and on April 6, 1919, arrived in Novorossiysk.

After returning to Southern Russia, Flug was entrusted in May 1919 with carrying out an inspection of all logistical institutions under the authority of the Special Meeting.

In September 1919, he was appointed an assistant to the military unit of the commander-in-chief and commander of the Kiev region, General Dragomirov.